Resumo O cromo (VI), metal altamente tóxico, é um dos principais constituintes dos resíduos industriais. É liberado no solo e na água, causa problemas ambientais e de saúde de crescente preocupação pública em países em desenvolvimento como o Paquistão. O objetivo básico deste estudo foi o isolamento e a triagem de bactérias resistentes ao cromo de resíduos industriais coletados em Korangi e Lyari, Karachi (24˚52’46,0”N 66˚59’25,7”E e 24˚48’37,5”N 67˚06’52,6”E). Do total de 53 cepas isoladas, sete cepas bacterianas foram selecionadas por enriquecimento seletivo e identificadas com base em características morfológicas e bioquímicas. Essas cepas foram designadas como S11, S13, S17, S18, S30, S35 e S48, apresentaram alta resistência aos metais contra concentrações variáveis (100-1500 mg / l) de cromo. Já as cepas S35 e S48 foram identificadas por meio da sequência 16S rRNA e apresentaram 99% de similaridade com Bacillus paranthracis e Bacillus paramycoides. Além disso, as condições de crescimento incluindo temperatura e pH foram otimizadas e ambas as cepas bacterianas apresentaram crescimento máximo na temperatura de 30 ºC, enquanto seu pH ótimo foi observado em 7,5 e 6,5, respectivamente. Conclui-se que o potencial de resistência dessas bactérias resistentes ao cromo pode ser efetivamente utilizado na remoção de cromo de efluentes industriais contaminados. Técnicas de base biológica usando bactérias ajudarão a fornecer métodos mais baratos e ecológicos de remoção, recuperação e desintoxicação de cromo.

Abstract Chromium (VI) a highly toxic metal, a major constituent of industrial waste. It is continuously release in soil and water, causes environmental and health related issues, which is increasing public concern in developing countries like Pakistan. The basic aim of this study was isolation and screening of chromium resistant bacteria from industrial waste collected from Korangi and Lyari, Karachi (24˚52ʹ46.0ʺN 66˚59ʹ25.7ʺE and 24˚48ʹ37.5ʺN 67˚06ʹ52.6ʺE). Among total of 53 isolated strains, seven bacterial strains were selected through selective enrichment and identified on the basis of morphological and biochemical characteristics. These strains were designated as S11, S13, S17, S18, S30, S35 and S48, resistance was determined against varying concentrations of chromium (100-1500 mg/l). Two bacterial strains S35 and S48 showed maximum resistance to chromium (1600 mg/l). Bacterial strains S35 and S48 were identified through 16S rRNA sequence and showed 99% similarity to Bacillus paranthracis and Bacillus paramycoides. Furthermore, growth condition including temperature and pH were optimized for both bacterial strains, showed maximum growth at temperature 30ºC and at optimum pH 7.5 and 6.5 respectively. It is concluded that indigenous bacterial strains isolated from metal contaminated industrial effluent use their innate ability to transform toxic heavy metals to less or nontoxic form and can offer an effective tool for monitoring heavy metal contamination in the environment.

Abstract This study investigated the synergy testing of penicillin, cephalosporin, amphenicols, and aminoglycoside in the camel milk (n=768 samples), subsequently used for isolation of MDR S. aureus targeting mecA gene. Antibiotic susceptibility of S. aureus showed >90% isolates were sensitive to ciprofloxacin and trimethoprim and resistant against oxacillin, ampicillin, and cefoxitin. Further, 50-85% of the S. aureus were sensitive to gentamicin, oxytetracycline, and chloramphenicol and resistant against cefotaxime, vancomycin, and cefixime. Minimum inhibitory concentration (MIC) of cefotaxime, (C) and ampicillin (A) in combination with gentamicin (G) was reduced by 99.34% and 70.46%, respectively, while with chloramphenicol (Ch), reduction was 57.49% and 60%, respectively. In addition, the Fractional Inhibitory Concentration Index (FICI) of G+A, Ch+C and Ch+G combinations showed synergy against 80%, 60%, and 30% of MDR S. aureus, respectively. Similarly, C+A and Ch+G displayed indifferent interaction against 70 % and 30% of isolates, respectively, while the later showed additive interaction against 10% of MDR S. aureus. Altogether, our results described effective combination of gentamicin and chloramphenicol with ampicillin and cefotaxime to combat MDR S. aureus.

Abstract In modern agriculture the use of biostimulants not only reduces the cost of production but also increase yield and quality of crops without harming environment. The response of fodder oat to biostimulants was evaluated in a pot experiment using four biostimulants at different concentrations i.e Moringa leaf extract at ratio of 1:10, 1:20, 1:30, 1:40, 1:50, Sea weed extract at 1%, 2%, 3%, 4%, 5%, Thiourea at 100 ppm, 200 ppm, 300 ppm, 400 ppm, 500 ppm and Chitosan at 25 ppm, 50 ppm, 100 ppm, 125 ppm, 150 ppm. Oat crop was treated with biostimulants using foliar application, at two growth stages i.e tillering and booting. Data on various agronomic and quality parameters were recorded and analyzed. Results showed that biostimulants significantly affected phenology and quality of oat. The highest green fodder yield (872.32 g) was observed in the pots treated with 2%Solution of seaweed extract similarly highest dry matter yield was also highest at 170.85 g Interestingly crude protein was highest for thiourea at 400 ppm. In each biostimulant following doses stood out both in terms of yield and quality. In case of moringa leaf extract the ratio of 1:40with 900 g per pot yield and 9.43 % protein, for sea weed extract 2% was better than other doses with 981 g yield and 9.17% protein, for thiourea the 400 ppm was better than other concentrations as it shows highest yield (872.32 g) and crude protein (9.52%) and for chitosan 100 ppm was comparatively better in performance with 964.98 g yield per pot and 9.35% CP. It is concluded from our study that biostimulants improve fodder oat yield and quality.

ABSTRACT To determine the mutagen agent potency and deduce an optimum dose, cytological analysis for induced chromosomal aberrations is considered as an accurate index in mutation breeding. Therefore, the present investigation was carried out to estimate the relative frequency and spectrum of meiotic abnormalities at various stages of cell division using Gamma rays, EMS and their combination treatments in M1 generation of black gram (Vigna mungo L. Hepper) varieties Pant U-30 and T-9. The analysis of M1 plants revealed a wide range of induced meiotic abnormalities like univalents, multivalents, laggards, chromatin bridges, micronuclei and chromosome stickiness by different mutagen doses. In addition to these, behavioral changes like precocious separation of chromosomes at metaphase, unequal separation of bivalents at anaphase, disturbed polarity and cytomixis at telophase were observed at low frequency. A linear relationship between the frequency of chromosomal aberrations and the strength of mutagen doses was observed in both the varieties and mutagen types. It was found that the combined treatments induced meiotic abnormalities at a higher frequency as compared to individual treatments of Gamma rays and EMS. Comparative estimation of induced cytological abnormalities suggested higher mutagenic sensitivity of var. Pant U-30 than the var. T-9 towards the treatments used. This also confirmed the relatively broader genetic tolerance level of black gram var. T-9 in inducing a significant amount of viable mutations without much lethality at the mutagen doses recommended in this study. Therefore, it can be concluded that the combine treatments of Gamma rays and EMS (300Gy+0.2%, 200Gy+0.3%) are relatively more effective for induction mutations in var. T-9 at the genotypic tolerable level.

RESUMEN Para determinar la potencia del agente mutagénico y una dosis óptima, el análisis citológico de las aberraciones cromosómicas inducidas se considera un índice adecuado en la inducción de mutaciones. Por lo tanto, la presente investigación se llevó a cabo para estimar la frecuencia relativa y el espectro de anormalidades meióticas en varias etapas de la división celular usando rayos Gamma, EMS y sus tratamientos combinados en la generación M1 de variedades de grano negro (Vigna mungo L. Hepper) Pant U-30 y T-9. El análisis de las plantas M1 reveló una amplia gama de anormalidades meióticas inducidas como univalentes, multivalentes, rezagados, puentes de cromatina, micronúcleos y adhesividad cromosómica por diferentes dosis de los agentes mutagénicos. Además de estos, se observaron cambios como la separación precoz de los cromosomas en la metafase, la separación desigual de los bivalentes en la anafase, la polaridad alterada y la citomixis en la telofase a baja frecuencia. Se observó una relación lineal entre la frecuencia de las aberraciones cromosómicas y la intensidad de las dosis de agentes mutagénicos, tanto en las variedades como en los tipos de agentes mutagénicos. Se encontró que los tratamientos combinados inducían anormalidades meióticas con mayor frecuencia en comparación con los tratamientos individuales de rayos Gamma y EMS. La estimación comparativa de las anormalidades citológicas inducidas sugirió una mayor sensibilidad mutagénica de la var. Pant U-30 que T-9 hacia los tratamientos utilizados. Esto también confirmó el nivel de tolerancia genética relativamente más amplio de la var. T-9 en la inducción de una cantidad significativa de mutaciones viables sin mucha letalidad a las dosis de los agentes mutagénicos recomendadas en este estudio. Por lo tanto, se puede concluir que los tratamientos combinados de rayos Gamma y EMS (300Gy + 0.2%, 200Gy + 0.3%) son relativamente más efectivos para la inducción de mutaciones en la var. T-9 en el nivel de tolerancia genotípica.

In the present study, samples of rhizosphere and root nodules were collected from different areas of Pakistan to isolate plant growth promoting rhizobacteria. Identification of bacterial isolates was made by 16S rRNA gene sequence analysis and taxonomical confirmation on EzTaxon Server. The identified bacterial strains were belonged to 5 genera i.e. Ensifer, Bacillus, Pseudomona, Leclercia and Rhizobium. Phylogenetic analysis inferred from 16S rRNA gene sequences showed the evolutionary relationship of bacterial strains with the respective genera. Based on phylogenetic analysis, some candidate novel species were also identified. The bacterial strains were also characterized for morphological, physiological, biochemical tests and glucose dehydrogenase (gdh) gene that involved in the phosphate solublization using cofactor pyrroloquinolone quinone (PQQ). Seven rhizoshperic and 3 root nodulating stains are positive for gdh gene. Furthermore, this study confirms a novel association between microbes and their hosts like field grown crops, leguminous and non-leguminous plants. It was concluded that a diverse group of bacterial population exist in the rhizosphere and root nodules that might be useful in evaluating the mechanisms behind plant microbial interactions and strains QAU-63 and QAU-68 have sequence similarity of 97 and 95% which might be declared as novel after further taxonomic characterization.